Hi Gamaliel
many things will change when you change the slice direction - amount of wrap, possibly your FOV, slab-selection profile if your protocol is slab-selective, and some types of distortion. These will all change the image which will change our results. Of course even if you don't change anything you won't get identical results if you scan twice, but our longitudinal stream is pretty reliable. Andre van der Kouwe has acquitisiton recommendations here:
http://www.nmr.mgh.harvard.edu/~andre/FreeSurfer_recommended_morphometry_pro...
cheers Bruce
On Fri, 8 Apr 2016, Gamaliel Huerta Urrea wrote:
2016-04-08 12:09 GMT-03:00 Gamaliel Huerta Urrea gamaliel.huerta@uv.cl: Hello Freesurfers I'm trying to do volumetric reconstruction, i already have done this but. i wanted to see if for the same subject, with different directions of slices i have the same result, and obviously i had different results of volumetric measures. i have used the sequence FSPGR T1 ponderation, with the same parameters for both data acquisition; with voxel 1 mm3, but the direction is changed in both studies axial and sagittal. Both studies are in *.dcm format, and i used the next command for convert dicom to .mgz and after to apply recon-all process:
mri_convert firstdicom.dcm 001.mgz
I would like to know why would i have this problem?
There is some specific slice direction for this kind of study which is suitable ?
I'm interested in cerebellum volumetric information. I attached my results for volumetry.
Cheers
-- Gamaliel Huerta Ingeniero Civil Biomédico HealthCare Analytics Centro Interdisciplinario de Innovación en Salud Universidad de Valparaíso
-- Gamaliel Huerta Ingeniero Civil Biomédico HealthCare Analytics Centro Interdisciplinario de Innovación en Salud Universidad de Valparaíso